Service manual

T r o u b l e s h o o T i n g T r e e s • C o m b i t h e r m C t e x p r e s s t e C h n i C a l s e r v i C e m a n u a l • D – 5
troubleshooting trees
No Convection Element Heat with Retherm Option (208-240V, 3PH)
Is N-6 or B5 below set
point?
Is K-41 contactor coil
energized?
Is K-41 contactor closing?
One must be below
set point in order for
convection elements to be
active in Retherm
No
Yes
Yes
No
L1/A1 from RBH X4/412, L2/A2
from N7 high limit through A2
on K-42 contactor
No
Yes
Replace K-41 contactor
L1/L2 supplied from TB 1/3
Is L1/L2 voltage across
terminals 2/4 on K-41
contactor?
No
Is voltage across terminals
1/3 on K-41 contactor?
Replace K-41 contactor
Is L3 power at terminal 6
of K-42 contactor?
L3 supplied to K-41/6
from TB 5
Is K-42 contactor coil
energized?
A1/L1 supplied from RBH X4/410, A2/L2
supplied from N7 high limit through K-61
N/C contacts (if Browning Bar option)
Is L3 power at terminal 5 of
K-42 contactor?
No
Yes
Yes
No
No
Yes
Yes
Replace K-42 contactor
No
Yes
Is voltage across E-41
convection elements?
Repair wiring between
K-41 and E-41
No
Yes
Is E-41 drawing current on
all legs?
Ohm out E-41 element
and replace if necessary
No
Yes
Convection Retherm cycle
is operating